The Stanford Stop Smoking Program (SSSP) is an on-going cigarette smoking research program with funding from both NCI and NHLBI. The research program has as its primary foci the development and testing of self-administered relapse prevention programs combining behavioral and pharmacological treatments and the study of potential risk factors for relapse following cessation. Funding for the SSP was provided by NCI and NHLBI at the time that Dr. Killen was Senior Research Scientist, Department of Medicine, Stanford University School of Medicine and Co-Principal Investigator on the project. The Principal Investigator (Dr. Killen) functioned as the Director of Research for two studies and directed the teams which developed the intervention materials and instrument and data collection protocols.